- Nick Adams
- Astronaut Glenn Amer
- Akira Takarada
- Astronaut K. Fuji
- Jun Tazaki
- Dr. Sakurai
- Akira Kubo
- Tetsuo Teri
- Kumi Mizuno
- Miss Namikawa
- Keiko Sawai
- Haruno Fuji
- Yoshio Tsuchiya
- Controller of Planet X
- Takamaru Sasaki
- Chairman of Earth Committee
- Gen Shimizu
- Minister of Defense
- Kenzô Tabu
- Commander from Planet X
- Yoshifumi Tajima
- General
- Nadao Kirino
- Military Aide
- Kôji Uno
- Namikawa's Associate
- Tôru Ibuki
- Xian
- Kazuo Suzuki
- Xian
- Fuyuki Murakami
- Councilman
- Noriko Sengoku
- Female Delegate
- Someshô Matsumoto
- Buddhist Priest
- Kamayuki Tsubono
- Councilman / Reporter
- Toki Shiozawa
- Minister
- Yasuhisa Tsutsumi
- Official
- Rinsaku Ogata
- Soldier
- Masaaki Tachibana
- Space Science Bureau Officer
- Yutaka Oka
- Reporter
- Saburô Iketani
- News Reader
- Yoshizo Tatake
- Xian
- Mitsuo Tsuda
- Self Defense Force Soldier
- Hideki Furukawa
- Xian
- Ryôji Shimizu
- Xian
- Minoru Itô
- Xian
- Takuzô Kumagai
- Xian
- Tadashi Okabe
- Space Bureau Officer / Reporter
- Haruo Nakajima
- Gojira
- Masaki Shinohara
- Radon
- Shôichi Hirose
- Kingugidora
- Marvin Miller
- Fuji
- Gorô Naya
- Councilman
- Hiroshi Akitsu
- Defense Corps Executive
- Peter Fernandez
- Tetsuo
- Bin Furuya
- Planet X Alien
- Kazuo Hinata
- Space Bureau Staff Member
- Yoshio Katsube
- Sekai Kyoikusha Employee (Planet X Alien)
- Shigeo Katô
- JSDF member
- Eisaburo Komatsu
- Space Bureau Official / Diet Audience Member (uncredited)
- Akio Kusama
- Government Official
- Keiji Sakakida
- Government official
- Haruya Sakamoto
- Self Defense Force Personnel
- Kôichi Satô
- Space Bureau Officer / Self-Defense Force Member (uncredited)
- Junnosuke Suda
- Official
- Sôji Ubukata
- Government Official
- Akira Wakamatsu
- Xian
- Osman Yusuf
- Restaurant patron
